Buggy code:
static final int DEFAULT = 1 ; static final int EXPLICIT_RECEIVER = 0 ; static final int NO_RECEIVER = - 1 ; static final int SUPER_RECEIVER = - 2 ; static final int NAME_RECEIVER = - 3 ; static final int ALLOCATION = - 4 ; static final int QUALIFIED_ALLOCATION = - 5 ; static final int QUESTION = 1 ; static final int COLON = 2 ; int invocationType ; int qualifier ; int lastModifiers = AccDefault ; int lastModifiersStart = - 1 ; int bracketDepth ; int canBeExplicitConstructor = CompletionParser . NO ; static final int NO = 0 ; static final int NEXTTOKEN = 1 ; static final int YES = 2 ; public CompletionParser ( ProblemReporter problemReporter , long sourceLevel ) { } public char [ ] assistIdentifier ( ) { } protected void attachOrphanCompletionNode ( ) { } private void buildMoreCompletionContext ( Expression expression ) { } public int bodyEnd ( AbstractMethodDeclaration method ) { } public int bodyEnd ( Initializer initializer ) { } private boolean checkCatchClause ( ) { } private boolean checkClassInstanceCreation ( ) { } private boolean checkClassLiteralAccess ( ) { } private boolean checkKeyword ( ) { } private boolean checkInstanceofKeyword ( ) { } private boolean checkInvocation ( ) { } private boolean checkMemberAccess ( ) { } private boolean checkNameCompletion ( ) { } private boolean checkRecoveredMethod ( ) { } private boolean checkRecoveredType ( ) { } public void completionIdentifierCheck ( ) { } protected void consumeArrayCreationExpressionWithInitializer ( ) { } protected void consumeArrayCreationExpressionWithoutInitializer ( ) { } protected void consumeAssignment ( ) { } protected void consumeAssignmentOperator ( int pos ) { } protected void consumeBinaryExpression ( int op ) { } protected void consumeCaseLabel ( ) { } protected void consumeCastExpression ( ) { } protected void consumeCastExpressionLL1 ( ) { } protected void consumeClassBodyDeclaration ( ) { } protected void consumeClassBodyopt ( ) { } protected void consumeClassHeaderName ( ) { } protected void consumeClassHeaderExtends ( ) { } protected void consumeClassTypeElt ( ) { } protected void consumeConditionalExpression ( int op ) { } protected void consumeConstructorBody ( ) { } protected void consumeConstructorHeader ( ) { } protected void consumeConstructorHeaderName ( ) { } protected void consumeDefaultLabel ( ) { } protected void consumeEnterAnonymousClassBody ( ) { } protected void consumeEnterVariable ( ) { } protected void consumeEqualityExpression ( int op ) { } protected void consumeExitVariableWithInitialization ( ) { } protected void consumeExplicitConstructorInvocation ( int flag , int recFlag ) { } protected void consumeFieldAccess ( boolean isSuperAccess ) { } protected void consumeForceNoDiet ( ) { } protected void consumeFormalParameter ( ) { } protected void consumeInsideCastExpression ( ) { } protected void consumeInsideCastExpressionLL1 ( ) { } protected void consumeInstanceOfExpression ( int op ) { } protected void consumeInterfaceHeaderName ( ) { } protected void consumeInterfaceType ( ) { } protected void consumeMethodInvocationName ( ) { } protected void consumeMethodInvocationPrimary ( ) { } protected void consumeMethodInvocationSuper ( ) { } protected void consumeMethodHeaderName ( ) { } protected void consumeMethodHeaderParameters ( ) { } protected void consumeMethodHeaderExtendedDims ( ) { } protected void consumeMethodBody ( ) { } protected void consumeMethodHeader ( ) { } protected void consumeModifiers ( ) { } protected void consumeRestoreDiet ( ) { } protected void consumeStatementSwitch ( ) { } protected void consumeNestedMethod ( ) { } protected void consumePushPosition ( ) { } protected void consumeToken ( int token ) { } protected void consumeUnaryExpression ( int op ) { } protected void consumeUnaryExpression ( int op , boolean post ) { } public ImportReference createAssistImportReference ( char [ ] [ ] tokens , long [ ] positions , int mod ) { } public ImportReference createAssistPackageReference ( char [ ] [ ] tokens , long [ ] positions ) { } public NameReference createQualifiedAssistNameReference ( char [ ] [ ] previousIdentifiers , char [ ] assistName , long [ ] positions ) { } public TypeReference createQualifiedAssistTypeReference ( char [ ] [ ] previousIdentifiers , char [ ] assistName , long [ ] positions ) { } public NameReference createSingleAssistNameReference ( char [ ] assistName , long position ) { } public TypeReference createSingleAssistTypeReference ( char [ ] assistName , long position ) { } public CompilationUnitDeclaration dietParse ( ICompilationUnit sourceUnit , CompilationResult compilationResult , int cursorLoc ) { } public void flushAssistState ( ) { } protected NameReference getUnspecifiedReferenceOptimized ( ) { } public void initialize ( ) { } private void initializeForBlockStatements ( ) { } public void initializeScanner ( ) { <START_BUG> this . scanner = new CompletionScanner ( this . assertMode ) ; <END_BUG> } private boolean isAfterArrayType ( ) { } private boolean isEmptyNameCompletion ( ) { } protected boolean isIndirectlyInsideBlock ( ) { } protected boolean isInsideBlock ( ) { } protected boolean isInsideBreakable ( ) { } protected boolean isInsideLoop ( ) { } protected boolean isInsideReturn ( ) { } public CompilationUnitDeclaration parse ( ICompilationUnit sourceUnit , CompilationResult compilationResult , int cursorLoc ) { } public void parseBlockStatements ( ConstructorDeclaration cd , CompilationUnitDeclaration unit ) { } protected void prepareForBlockStatements ( ) { } private void pushCompletionOnMemberAccessOnExpressionStack ( boolean isSuperAccess ) { } public void recordCompletionOnReference ( ) { } public void recoveryExitFromVariable ( ) { } public void recoveryTokenCheck ( ) { } protected void reportSyntaxError ( int act , int currentKind , int stackTop ) { } public void reset ( ) { } public void resetAfterCompletion ( ) { } protected boolean resumeAfterRecovery ( ) { } public void setAssistIdentifier ( char [ ] assistIdent ) { } public String toString ( ) { } protected void updateRecoveryState ( ) { } protected LocalDeclaration createLocalDeclaration ( Expression initialization , char [ ] assistName , int sourceStart , int sourceEnd ) { } protected FieldDeclaration createFieldDeclaration ( Expression initialization , char [ ] assistName , int sourceStart , int sourceEnd ) { } }

Fix:
this . scanner = new CompletionScanner ( this . sourceLevel ) ;